WARNING: The following contains spoilers for "The World of No Return" by Jason Aaron, Aaron Kuder, Dean White, and VC's Cory Petit, from Heroes Reborn #7, on sale now.
The world of Heroes Reborn has seen its heroes, the Squadron Supreme, haunted by the ghosts of a reality they have never known, and they are spiraling towards a confrontation with the Avengers, who were plucked out of history in their world.
While the Squadron's history might be very different from the Marvel Universe's history, some parts of it still rhyme, and this timeline saw a superhero Civil War years earlier that cemented a lasting resentment between Hyperion and Nighthawk. The latest issue of Heroes Reborn #7 opens with a horrifying scene of Hyperion flying straight towards Nighthawk over the wreckage of Connecticut, which the entire state nearly destroyed by a battle between the heroes.
Much like 2006's Civil War by Mark Millar and Steve McNiven, the superhero civil war of Mephisto's reality split the caped community in half over a Superhero Registration Act. While the impetus of the law in Heroes Reborn hasn't been explicitly stated, the fact that Nighthawk, who is staunchly against it, it a seated United States Senator does complicate matters. However, that isn't the only reason for him to go to war with fellow Squadron Supreme member Hyperion, as the latter hero points out that the love triangle between himself, Power Princess, and Nighthawk is a large part of the tension between them that has boiled over into bloodshed.
Love may be part of the animosity that Kyle Richmond feels towards Hyperion, but it is not the only thing that Nighthawk is fighting for. He makes it clear that his motives as a Senator and as a superhero are vastly different, even if they are both ultimately in the service of the greater good. Like Captain America, Nighthawk has no problem compartmentalizing his patriotism with his sense of morality, and the Superhero Registration Act crosses both sides of that line in ways that the hero cannot abide.
Nighthawk is dedicated to winning this war, and he is willing to go to any lengths to do so, as pointed out by Hyperion when he mentions his disgust at seeing him bonded to the Venom symbiote of this world and wearing the Eye of Agamotto. The original Civil War never really saw any of its heroes pulling their punches, although it certainly didn't see very many of them go so far as Nighthawk has, and few moments were as shocking as seeing Hyperion fly his longtime friend into the Sun.
With the end of Heroes Reborn drawing closer, the finer details of this superhero war will almost certainly go untold. However, the Squadron's inevitable fight with the Avengers will likely see the heroes of this timeline go to war one last time.